I used to use Inventor professionally, and that had a MTBF of perhaps 4 hours. I haven't needed a CAD program since then, but one of the things that'd make me try Solvespace first is that whitequark appears to actually care about reliability.
Even in case that SolveSpace does crash, it has an autosave facility (with a five minute interval by default), and so you should never lose more than five minutes of work.
You should also use the 2.x branch and not the released version 2.1, as the branch has some important bugfixes. I will release 2.2 within a few of days though.
Also, I find solvespace much easier to use the Freecad. Freecad has such a myriad of options and controls that I find myself often taking a while to find the one I'm looking for. Solvespace is a much more focused tool, having fewer but easier to find controls.